In this Thursday, May 2, 2013 photo, Iran's former nuclear negotiator, Hasan Rohani, a potential front-runner in the presidential race, waves to his supporters in a campaign rally in Tehran, Iran. For eight years, Iran’s President Mahmoud Ahmadinejad has played the role of global provocateur-in-chief: questioning the Holocaust, saying Israel should be erased from the map and painting U.N resolutions as worthless. Now, a race is beginning to choose his successor -- candidate registration starts Tuesday for a June 14 vote -- and it looks like an anti-Ahmadinejad referendum is shaping up. (AP Photo/Vahid Salemi)